Air Conditioning

[SilverT4]

When I start my Prius from cold, after a few seconds there is a shudder and then what sounds like the petrol engine starting up. I couldnt figure out why this would happen as I was still stationary, but after checking the screen, I realised that it wasn't the petrol engine and then I figured it was the A/C motor. Switching A/C off and on confirmed this. After a couple of miles, the noise dies down and stopping and starting the A/C seems quiet as I would expect it to be. Anyone else having this problem ?

[Braindead]

Not convinced it's the air con. I figured it might be as follows:

Air con set to auto.

Internal car temp set to higher than external temp

Car leaves blower off as temp outside lower than inside

Car figures out it needs heat

Car Starts engine to get heat

As engine gets up to temperature, blower comes on high and heats car

Engine may stop as it's up to temperature but depends on how car is driven

As heat is taken from engine, it starts again for more heat.

On the other hand, I could be wrong!

[SilverT4]

Sounds possible, but the energy monitor doesn't show the petrol engine running. I need to do some more testing on this at weekend. I'll let you know the results.

[Braindead]

If I understand the beast correctly - the engine only shows as running when driving the wheels or charging the batteries.

Tell you what, go to the "Climate" panel, press "Auto" to put it in automatic climate control and then make sure air con is not active by looking at the "Air Con" button at the top left. If it is (yellow bar over the button) press the button to turn it off.

The climate control will work but without the air con and I bet the engine comes on.

[SilverT4]

I think you are right about the ar con. I left it switched off today and the problem disappeared. But I thought the climate control was fully electric, so I am confused.

looks like leaving the A/C off until the car warms up improves petrol consumption even more.